1. Field
The subject invention relates to semiconductor processing tools and, in particular, to tools and methods for mounting transport rails in a vacuum processing tool.
2. Related Art
Substrate processing tools are used to make disks, computer chips, solar panels, and the like, from semiconductor wafers or similar substrates. Typically, the substrate processing tools includes several substrate chambers that perform various processes that modify the substrate, such as, deposition, cleaning, heat/cool, etc. In disk processing systems, the disks are transported in the substrate processing tool by a carrier riding on transport rails that form a drive track.
In current substrate processing tools, the transport rails are mounted to the chamber walls or the motor housing of the transport mechanism. Fasteners secure the transport rails via an angle bracket. This mounting configuration is both time consuming to install and is difficult to maintain. For example, during operation of the tool, the repetitive movements of the carrier sometimes cause the fasteners to loosen or even become lost, requiring either tightening or replacement of the fasteners.
In addition, alignment of the transport rails is necessary for smooth transport of the wafers. Alignment with the bracket and fastener configuration is challenging because of a tolerance stack-up in the parts, which can cause the rail to be out of alignment in one axis (i.e., not perpendicular to the system). In order to align the transport rails with one another, tools such as clamps or laser sights are often required to align each of the individual rails with the next station. Slot valves (or other isolation valves) that separate the chambers can also interfere with the alignment.